Nonunion and Malunion Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Nonunion and Malunion. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Nonunion and Malunion Indian Medical PG Question 1: Nonunion is most common in fracture of the:
- A. Talus
- B. Neck femur (Correct Answer)
- C. Scapula
- D. None of the options
Nonunion and Malunion Explanation: ***Neck femur***
- Fractures of the **femoral neck** are highly prone to **nonunion** due to the precarious and often-disrupted blood supply to the femoral head, particularly the **retinacular arteries**.
- The high biomechanical stress and difficulty in achieving stable fixation in this region further contribute to the increased risk of nonunion.
*Talus*
- While talar fractures, especially those of the **talar neck**, can have a high incidence of complications like **avascular necrosis** due to limited blood supply, nonunion is less common than in femoral neck fractures.
- The talus has a complex vascular network that, while vulnerable, often allows for healing.
*Scapula*
- **Scapular fractures** are generally uncommon and, when they occur, typically heal well without surgical intervention.
- Due to the surrounding musculature and rich vascular supply, nonunion of the scapula is extremely rare.
*None of the options*
- This option is incorrect because **nonunion is indeed a significant problem** in specific fractures, particularly those of the femoral neck, making it a viable answer.
Nonunion and Malunion Indian Medical PG Question 2: The malunion of a supracondylar fracture of the humerus most commonly leads to:
- A. Cubitus varus (Correct Answer)
- B. Cubitus valgus
- C. Extension deformity
- D. Flexion deformity
Nonunion and Malunion Explanation: ***Cubitus varus***
- A **supracondylar fracture** malunion often results in posterior and medial displacement of the distal fragment, leading to a **loss of the carrying angle** or even its reversal, known as **cubitus varus** or **gunstock deformity**.
- This characteristic deformity is the most common and recognizable long-term complication of improperly healed supracondylar humerus fractures.
*Flexion deformity*
- While some limitation of extension can occur, a pure **flexion deformity** is not the most common or defining malunion pattern for supracondylar fractures.
- The primary angular deformity is typically in the coronal plane (varus) rather than the sagittal plane (flexion/extension).
*Cubitus valgus*
- **Cubitus valgus** is an increased carrying angle, where the forearm deviates laterally, and is relatively rare after supracondylar fracture malunion.
- It is more commonly associated with **lateral condyle fractures** or physeal injuries.
*Extension deformity*
- An **extension deformity** would imply an increase in the normal extension of the elbow, which is not a common consequence of supracondylar fracture malunion.
- The typical angular malunion involves either varus or, less commonly, some degree of flexion contracture.
Nonunion and Malunion Indian Medical PG Question 3: McMurray's osteotomy is done for
- A. Malunited intertrochanteric fracture of femur
- B. Malunited supracondylar fracture of humerus
- C. Nonunion lateral condyle fracture of humerus
- D. Nonunion transcervical neck fracture of femur (Correct Answer)
Nonunion and Malunion Explanation: ***Nonunion transcervical neck fracture of femur***
- **McMurray's osteotomy** was historically performed for **nonunion of femoral neck fractures**, particularly transcervical, to improve blood supply and encourage healing.
- The procedure involves an **intertrochanteric osteotomy** which changes the biomechanics of the hip, promoting compression at the fracture site.
*Malunited intertrochanteric fracture of femur*
- This osteotomy is not typically indicated for **malunited intertrochanteric fractures**, as these usually heal well and subsequent malunion is managed differently if symptomatic.
- Intertrochanteric fractures often have an **excellent blood supply**, making nonunion less common than in transcervical fractures.
*Malunited supracondylar fracture of humerus*
- **Malunited supracondylar fractures of the humerus** are managed according to the deformity, often with corrective osteotomies specific to the humerus, not McMurray's osteotomy.
- McMurray's osteotomy is a procedure designed for the **femur** and hip joint biomechanics.
*Nonunion lateral condyle fracture of humerus*
- **Nonunion of lateral condyle fractures of the humerus** is a problem of the elbow joint and is treated with local procedures such as open reduction and internal fixation with bone grafting.
- This fracture type is in the **upper limb** and has no relation to the hip-focused McMurray's osteotomy.
Nonunion and Malunion Indian Medical PG Question 4: Elephant foot deformity is indicative of:
- A. Unilateral Le Fort I fracture of maxilla
- B. Non-union of fractured edentulous mandible (Correct Answer)
- C. Diplopia
- D. Skeletal Class II malocclusion
Nonunion and Malunion Explanation: ***Non-union of fractured edentulous mandible***
- An **elephant foot deformity** is a characteristic radiographic finding in the non-union of a fracture, particularly in the context of an **edentulous mandible**.
- It describes the appearance of **sclerotic, hypertrophic bone ends** at the fracture site, resembling the thick, club-like foot of an elephant, due to persistent movement and attempted callus formation.
*Diplopia*
- **Diplopia** refers to the perception of two images from a single object, often caused by ophthalmological or neurological issues affecting eye movement.
- It is a symptom related to vision and has no association with bone deformities or fracture healing patterns.
*Skeletal Class II malocclusion*
- **Skeletal Class II malocclusion** describes a condition where the mandible is retrognathic (set back) relative to the maxilla, resulting in an "overbite."
- This is a developmental craniofacial anomaly related to jaw position, not a characteristic sign of fracture non-union.
*Unilateral Le Fort I fracture of maxilla*
- A **unilateral Le Fort I fracture of the maxilla** is a midfacial fracture that separates the maxilla from the pterygoid plates and nasal septum, usually involving a horizontal fracture line above the maxillary teeth.
- While it is a type of facial fracture, it does not typically result in an "elephant foot deformity," which is specific to hypertrophic non-unions, especially in the mandible.
Nonunion and Malunion Indian Medical PG Question 5: Which of the following fractures is least likely associated with vascular injury?
- A. Fracture supracondylar femur
- B. Fracture supracondylar humerus
- C. Fracture shaft of femur
- D. Fracture shaft of humerus (Correct Answer)
Nonunion and Malunion Explanation: ***Fracture shaft of humerus***
- While any fracture can theoretically cause vascular injury, **mid-shaft humeral fractures** are less commonly associated with significant **vascular compromise** compared to those around major joints or near critical neurovascular bundles.
- The **brachial artery** and its branches are often sufficiently mobile and protected by surrounding musculature in the mid-shaft region, reducing the incidence of direct laceration or entrapment.
*Fracture supracondylar femur*
- **Supracondylar femur fractures** are in close proximity to the **femoral artery** and its branches in the popliteal fossa.
- Displacement of these fractures can easily **lacerate or compress** these vital vessels, leading to high rates of vascular injury.
*Fracture supracondylar humerus*
- **Supracondylar humerus fractures** in children are notoriously associated with **brachial artery injury** due to the artery's close proximity and fixated position over the joint.
- The acute angulation and displacement often seen in these fractures put the artery at significant risk of **kinking, compression, or transection**.
*Fracture shaft of femur*
- **Femoral shaft fractures** can be associated with significant vascular injury, particularly from **large displaced fragments** or high-energy trauma.
- The **superficial femoral artery** and its perforating branches can be torn, leading to substantial hemorrhage or arterial compromise.
Nonunion and Malunion Indian Medical PG Question 6: The commonest complication of fracture of clavicle is :
- A. non union
- B. avascular necrosis
- C. Neurovascular injury
- D. malunion (Correct Answer)
Nonunion and Malunion Explanation: ***malunion***
- **Malunion** is the most frequent complication following a clavicle fracture, meaning the bone heals in an anatomically incorrect or deformed position.
- This often results in a palpable bump or cosmetic deformity, and can occasionally cause functional impairment.
*non union*
- **Non-union** occurs when the fracture fails to heal completely, leaving a persistent gap between the bone fragments.
- While possible, it is less common than malunion in clavicle fractures, especially with appropriate management.
*avascular necrosis*
- **Avascular necrosis** is rare in clavicle fractures because the clavicle has a rich blood supply.
- It typically affects bones with precarious blood supply, such as the femoral head or scaphoid.
*Neurovascular injury*
- **Neurovascular injury** involving the subclavian vessels or brachial plexus is a serious but relatively rare complication of clavicle fractures.
- While possible, especially with displaced fractures, it is not the most common adverse outcome.
Nonunion and Malunion Indian Medical PG Question 7: Which of the following is false regarding clavicle?
- A. First bone to ossify
- B. Membranous ossification
- C. Fracture can be treated with figure of 8 bandage
- D. Non-union is the commonest complication of clavicle fractures (Correct Answer)
Nonunion and Malunion Explanation: ***Non-union is the commonest complication of clavicle fractures***
- While clavicle fractures are relatively common, **malunion** (healing in an imperfect position) is more frequent than non-union.
- **Non-union** typically occurs in less than 5% of all clavicle fractures, making it a rare complication rather than the commonest.
*First bone to ossify*
- The clavicle is indeed the **first bone to ossify** in the human embryo, beginning around the 5th to 6th week of gestation.
- This characteristic highlights its unique developmental pathway compared to most other bones.
*Membranous ossification*
- The clavicle develops primarily through **intramembranous ossification**, which involves direct ossification of mesenchymal tissue without a cartilaginous precursor.
- It's one of the few bones in the body, along with some bones of the skull, that ossifies this way.
*Fracture can be treated with figure of 8 bandage*
- A **figure-of-eight bandage** was historically used for clavicle fractures to provide reduction and immobilization.
- However, current evidence suggests that a **simple sling** is equally effective and often more comfortable, with less risk of complications like neurovascular compression.
Nonunion and Malunion Indian Medical PG Question 8: Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-
- A. Distal 1/3
- B. Proximal 1/3 (Correct Answer)
- C. Scaphoid Tubercle fracture
- D. Middle 1/3
Nonunion and Malunion Explanation: ***Proximal 1/3***
- The **proximal pole of the scaphoid** has a precarious blood supply, primarily from retrograde extraosseous vessels entering distally. A fracture in this region can compromise this supply, leading to **avascular necrosis (AVN)**.
- Due to the limited blood flow to the proximal fragment, healing is often impaired, increasing the risk of **non-union** and **malunion**.
*Distal 1/3*
- Fractures in the **distal 1/3 (distal pole)** of the scaphoid typically have a better prognosis.
- This area has a more robust blood supply, reducing the risk of AVN and promoting faster healing.
*Scaphoid Tubercle fracture*
- Fractures of the **scaphoid tubercle** are usually considered stable and intra-articular, with a good blood supply.
- These fractures generally heal well with conservative treatment and have a very low incidence of AVN or non-union.
*Middle 1/3*
- Fractures in the **middle 1/3 (waist)** of the scaphoid are the most common but still pose a significant risk of non-union.
- While the risk of AVN is lower than for proximal pole fractures, it is still higher than for distal fractures, due to the critical vascular supply to both fragments.
Nonunion and Malunion Indian Medical PG Question 9: Treatment of choice for displaced fracture neck femur in a 40 years old female
- A. None of the options
- B. Bipolar hemiarthroplasty
- C. Multiple screw fixation (Correct Answer)
- D. THR
Nonunion and Malunion Explanation: ***Multiple screw fixation***
- For a **displaced femoral neck fracture** in a younger patient (40 years old), **internal fixation** with multiple screws is generally the preferred treatment to preserve the native **femoral head**.
- This approach aims to achieve **anatomical reduction** and stable fixation, allowing for bone healing and a better long-term functional outcome in active individuals.
*Bipolar hemiarthroplasty*
- This procedure is typically reserved for older, less active patients with **displaced femoral neck fractures**, particularly those with pre-existing conditions that might limit their longevity or activity level.
- While it replaces the femoral head, it does not preserve the native joint, which is a less desirable outcome in a 40-year-old.
*THR*
- **Total hip replacement** is usually considered for older patients, or younger patients with **pre-existing arthritis** or failed internal fixation, due to concerns about the prosthesis's longevity and potential future revisions.
- In a 40-year-old, the goal is typically to preserve the native joint if possible, unless there are other complicating factors.
*None of the options*
- Internal fixation with multiple screws is a well-established and appropriate treatment for a displaced femoral neck fracture in a 40-year-old patient.
- Therefore, one of the provided options is indeed the correct treatment choice for this specific scenario.
Nonunion and Malunion Indian Medical PG Question 10: Which of the following bone defects offers the best chance for bone fill?
- A. 3 Walled defect (Correct Answer)
- B. Hemisepta
- C. Osseous crater
- D. 2 Walled defect
Nonunion and Malunion Explanation: ***3 Walled defect***
- A **3-walled defect** provides the best prognosis for bone fill because it retains the most natural bone structure, enhancing the ability to contain bone graft material effectively.
- The presence of three bony walls offers **excellent support and blood supply** for graft survival and successful bone regeneration.
*Hemisepta*
- A **hemisepta** refers to a one-walled defect, which offers very limited containment for graft materials.
- It has a **poor prognosis** for bone fill due to insufficient support and rapid loss of grafting material.
*Osseous crater*
- An **osseous crater** is a two-walled defect where the buccal and lingual walls are present, but the interproximal walls are missing.
- While better than a one-walled defect, it still presents challenges in graft containment and has a **less predictable outcome** compared to a 3-walled defect.
*2 Walled defect*
- A **2-walled defect** offers less containment and support for bone graft materials compared to a 3-walled defect.
- The reduced number of walls means there is a **higher chance of graft material displacement** and a slower healing process.
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